FREE ACTION
Free actions consume a very small amount of time and effort. Their impact is so minor that they’re considered free. You can perform one or more free actions during your turn. However, the DM can put reasonable limits on what you can really do for free.
SWIFT ACTION
A swift action consumes a very small amount of time, but it represents a larger expenditure of effort than a free action. You can take a swift action any time during your turn, but you can perform only one swift action per turn.
IMMEDIATE ACTION
An immediate action consumes a tiny amount of time. However, unlike a swift action, an immediate action can be performed at any time during a round, even when it isn’t your turn. Using an immediate action on your turn counts as your swift action for that turn. If you use an immediate action when it isn’t your turn, you can’t use another immediate action or a swift action until after your next turn. You can’t use an immediate action when you’re flat-footed.
NOT AN ACTION
Some activities are so minor that they aren’t even con- sidered free actions. They literally don’t take any time at all to do and are considered an inherent part of doing something else.